I'm trying to create a simple test with nestjs, and I'm get this error
Test functions cannot both take a 'done' callback and return something. Either use a 'done' callback, or return a promise.
Returned value: Promise {}
The unit test is so simple, but I get an error when I use done();
it('throws an error if user signs up with email that is in use', async (done) => {
fakeUsersService.find = () => Promise.resolve([{ id: 1, email: 'a', password: '1' } as User]);
try {
await service.signup('asdf@asdf.com', 'asdf');
} catch (err) {
done();
}
});
You are combining Async/Await and Done.
Either use asnyc/await, or done.
it('throws an error if user signs up with email that is in use', async () => {
try {
await service();
expect(...);
} catch (err) {
}
});
or use the done format
it('throws an error if user signs up with email that is in use', (done) => {
...
service()
.then( ...) {}
.catch( ...) {}
}
done();
});
for the last version from jest, you can't use `async/await , promise and done together.
the solution is
it("throws an error if user sings up with email that is in use", async () => {
fakeUsersService.find = () =>
Promise.resolve([{ id: 1, email: "a", password: "1" } as User]);
await expect(service.signup("asdf@asdf.com", "asdf")).rejects.toThrow(
BadRequestException
);
});
change BadRequestException according to your listening exception
Also, if you want to use both you can downgrade your current version of jest to : 26.6.3. Worked fine for me, I'm using async + done